code: def test_input_shapes(self, layer):
      assert layer.input_shapes == [
          l.output_shape for l in layer.input_layers
      ]
  
imports: from mock import Mock
  import numpy
  import pytest
  import theano
label_desc: Use image node_id 2 for calling the TestMergeLayer obj's underlying member method code with example usage: obj.test_input_shapes(layer) without return types